Officers working in custody suites in the West Midlands must undergo more training after a man self-harmed in a cell, the police watchdog says.

The 21-year-old was held on suspicion of burglary, criminal damage and drug possession last August and detained at Willenhall police station in Coventry.

He self-harmed in the cell and later in hospital but was not seriously hurt.

The Independent Police Complaints Commission (IPCC) said officers did not show due diligence in their duties.

A number of recommendations have been made to West Midlands Police regarding the training for custody staff and officers, which includes refresher training for officers on how to handle "adverse incidents", the body said.

'Weaknesses identified'

"The investigation found that on both occasions the officers and police staff responsible for his care did not show due diligence in their duties and responsibilities following the incidents of self harm," an IPCC spokesman said.

"As a result three officers and one civilian member of staff have been subject to management action."

Len Jackson, IPCC Commissioner, said weaknesses had been identified.

He said: "I am thankful that this incident did not result in a more tragic outcome.

"Given this young man's attempt to self harm on two occasions while in police custody, it was right that we managed an investigation in an effort to ensure that the incidents were learned from.

"While West Midlands Police have carried out a great deal of work in relation to their custody polices and training, some weakness were still identified.

"The recommendations made, when implemented, should improve awareness and help minimise the risk of such incidents in the future. "